Application of a sentinel species-based population evaluation using creek chub (Semotilus atromaculatus), a common minnow in eastern North America, could provide a framework for environmental assessments and focus future research in small streams. Analysis of creek chub endpoints (growth, condition, fecundity) was based on an assessment framework for white sucker (Catostomus commersoni) populations (Gibbons & Munkittrick, 1994). We evaluated creek chub and fish community endpoints simultaneously in two streams with differing degrees of urbanization, agriculture, and thermal regimes during spring, summer, and fall. Fish from the more altered stream appear to be suffering from a feeding-based niche shift, and demonstrate reproductive anomalies suggestive of exposure to some unknown sublethal stressor(s). Fish community assessments identified modified habitat and water quality but did not detect the presence of any additional stressor(s). Similarity in fish community and population responses, widespread distribution of creek chub, limited within-stream movements, and the ability of this species to populate even the smallest streams where the resident fish community may be depauperate and fish community-type assessments limited, makes the potential use of creek chub as a monitor for small streams promising over a wide geographic zone.